The waiting time paradox: population based retrospective study of treatment delay and survival of women with endometrial cancer in Scotland

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Which role do excited states play in radiation damage to organic solid-state compounds?

Ionizing radiation induces radicals in organic materials. When such species are created in biological macromolecules like DNA, they harm living organisms. This detrimental effect is explicitly exploited for the sterilisation of e.g. foodstuffs, and radiation-induced radicals are quantitatively used for radiation dosimetry purposes. For understanding radiation actions at different levels of molecular and cellular organisation, knowledge of the radical structures and their formation mechanisms is of fundamental importance. In this context, radiation-induced processes in solid sugars are studied, among others, to gain insight into the role of the deoxyribose unit in the radiation chemistry of DNA. X-irradiation typically gives rise to a variety of primary radicals in these systems, which transform into stable radicals or diamagnetic species via one or more radical reactions. By combining electron magnetic resonance experiments and density functional theory (DFT) calculations, we recently identified the major stable [1,2], as well as the major primary [3] radiation-induced radicals in solid sucrose (see figure). We are currently investigating how the primary radicals transform into the stable ones. A general but important observation is that in sucrose and similar carbohydrates, e.g. rhamnose, the primary radical formation (typically by way of net H-abstraction) is selective: it preferentially takes place at particular carbons and oxygens. This selectivity apparently cannot be explained simply on thermodynamical grounds. It may be hypothesised that, after the initial oxidation event (leaving the radical cation in an excited state), the hole ‘migrates’ to a particular carbon or oxygen, after which de-excitation and deprotonation processes yield a neutral radical. It is our goal to examine factors possibly explaining the experimentally observed selectivity. So far we have made some preliminary ground-state calculations on energy profiles of deprotonation reactions in rhamnose single crystals, as well as time-dependent DFT calculations of excited states in this system

Winter climate affects long-term trends in stream water nitrate in acid-sensitive catchments in southern Norway

International audienceControls of stream water NO3 in mountainous and forested catchments are not thoroughly understood. Long-term trends in stream water NO3 are positive, neutral and negative, often apparently independent of trends in N deposition. Here, time series of NO3 in four small acid-sensitive catchments in southern Norway were analysed in order to identify likely drivers of long-term changes in NO3. In two sites, stream water NO3 export declined ca 50% over a period of 25 years while in the other sites NO3 export increased with roughly 20%. Discharge and N deposition alone were poor predictors of these trends. The most distinct trends in NO3 were found in winter and spring. Empirical models explained between 45% and 61% of the variation in weekly concentrations of NO3, and described both upward and downward seasonal trends tolerably well. Key explaining variables were snow depth, discharge, temperature and N deposition. All catchments showed reductions in snow depth and increases in winter discharge. In two inland catchments, located in moderate N deposition areas, these climatic changes appeared to drive the distinct decreases in winter and spring concentrations and fluxes of NO3. In a coast-near mountainous catchment in a low N deposition area, these climatic changes appeared to have the opposite effect, i.e. lead to increases in especially winter NO3. This suggests that the effect of a reduced snow pack may result in both decreased and increased catchment N leaching depending on interactions with N deposition, soil temperature regime and winter discharge

Influence of summer and winter climate variability on nitrogen wet deposition in Norway

Dominating wind patterns around Norway may change due to climate warming. This could affect transport of polluted air masses and precipitation. Here, we study relations between reactive nitrogen wet deposition and air mass transport during summer and winter expressed in the form of climate indices, at seven sites in Southern Norway for the period 1980–2005. Atmospheric nitrate concentrations decreased with 0 to 50% in the period, particularly at sites with little precipitation, and mostly during 1990–2005. For comparison, reported reductions in emissions of oxidised nitrogen in Europe in 1989–2003 were 23%. Climate indices explained up to 36% of the variation in winter nitrate deposition at the western and northern sites – and also explained 60% of the variation in winter precipitation (R=0.77). This suggests that the variation in nitrate wet deposition is closely related to variation in precipitation, and that the climate indices seem to also partly control the variation in atmospheric nitrate concentrations (R=−0.45 at coastal sites). At the coastal sites, local air temperature was highly correlated (R=0.84) with winter nitrate deposition, suggesting that warm, humid winter weather results in increased wet nitrate deposition. For ammonia the pattern was similar, but this compound is more influenced by local sources. Expected severe increase in precipitation in western and northern regions as a consequence of climate change suggest that nitrogen deposition in these areas will increase under global warming if emissions are held constant

Childhood IQ and cardiovascular disease in adulthood: prospective observational study linking the Scottish Mental Survey 1932 and the Midspan studies

This study investigated the influence of childhood IQ on the relationships between risk factors and cardiovascular disease (CVD), coronary heart disease (CHD) and stroke in adulthood. Participants were from the Midspan prospective cohort studies which were conducted on adults in Scotland in the 1970s. Data on risk factors were collected from a questionnaire and at a screening examination, and participants were followed up for 25 years for hospital admissions and mortality. 938 Midspan participants were successfully matched with their age 11 IQ from the Scottish Mental Survey 1932, in which 1921-born children attending schools in Scotland took a cognitive ability test. Childhood IQ was negatively correlated with diastolic and systolic blood pressure, and positively correlated with height and respiratory function in adulthood. For each of CVD, CHD and stroke, defined as either a hospital admission or death, there was an increased relative rate per standard deviation decrease (15 points) in childhood IQ of 1.11 (95% confidence interval 1.01-1.23), 1.16 (1.03-1.32) and 1.10 (0.88-1.36) respectively. With events divided into those first occurring before and those first occurring after the age of 65, the relationships between childhood IQ and CVD, CHD and stroke were only seen before age 65 and not after age 65. Blood pressure, height, respiratory function and smoking were associated with CVD events. Relationships were stronger in the early compared to the later period for smoking and FEV1, and stronger in the later compared to the earlier period for blood pressure. Adjustment for childhood IQ had small attenuating effects on the risk factor-CVD relationship before age 65 and no effects after age 65. Adjustment for risk factors attenuated the childhood IQ-CVD relationship by a small amount before age 65. Childhood IQ was associated with CVD risk factors and events and can be considered an important new risk factor

Quantitative assessment of two oil-in-ice surface drift algorithms

The ongoing reduction in extent and thickness of sea ice in the Arctic might result in an increase of oil spill risk due to the expansion of shipping activity and oil exploration shift towards higher latitudes. This work assessed the response of two oil-in-ice surface drift models implemented in an open-source Lagrangian framework. By considering two numerical modeling experiments, our main finding indicates that the drift models provide fairly similar outputs when forced by the same input. It was also found that using higher resolution ice-ocean model does not imply better results. We highlight the role of sea ice in the spread, direction and distance traveled by the oil. The skill metric seems to be sensitive to the drift location, and drift model re-initialization is required to avoid forecast deterioration and ensure the accurate tracking of oil slicks in real operations.publishedVersio

Estimating a mean transport velocity in the marginal ice zone using ice-ocean prediction systems

Understanding the transport of objects and material in the marginal ice zone (MIZ) is critical for human operations in polar regions. This can be the transport of pollutants, such as spilled oil, or the transport of objects, such as drifting ships and search and rescue operations. For emergency response, the use of environmental prediction systems are required which predict ice and ocean parameters and are run operationally by many centres in the world. As these prediction systems predict both ice and ocean velocities, as well as ice concentration, it must be chosen how to combine these data to best predict the mean transport velocities. In this paper we present a case study of four drifting buoys in the MIZ deployed at four distinct ice concentrations. We compare short-term trajectories, i.e. up to 48 h lead times, with standard transport models using ice and ocean velocities from two operational prediction systems. A new transport model for the MIZ is developed with two key features aimed to help mitigate uncertainties in ice–ocean prediction systems: first, including both ice and ocean velocities and linearly weighting them by ice concentration, and second, allowing for a non-zero leeway to be added to the ice velocity component. This new transport model is found to reduce the error by a factor of 2 to 3 for drifters furthest in the MIZ using ice-based transport models in trajectory location after 48 h.publishedVersio

Impacts of offshore oil spill accidents on island bird communities: A test run study around Orkney and Svalbard archipelagos

The sea area around the Orkney archipelago, Scotland is subjected to substantial maritime shipping activities. By contract, the Svalbard archipelago, Norway currently has a rather low marine traffic profile. Future projections, however, indicate that the Trans-Arctic route might change the whole transportation picture and Svalbard may be at the centre of maritime activities. Both archipelagos have sensitive environmental resources at sea and inland, including bird communities. There are, for instance, 13 Red Listed species present in Orkney and 2 in Svalbard. In this regard, it is important to address oil spill risks along existing and projected shipping routes. Hypothetical spills were simulated in twelve scenarios for both the Orkney and Svalbard archipelagos with the OpenDrift open-source software. The results indicate risks to seabird communities. For Orkney, the spills resulted in the most extensive contamination of the sea and land environments in autumn. For Svalbard, autumn spills on the contrary presented the lowest risk to seabirds. Based on the simulations, we recommend increased caution for shipping activities in the problematic seasons, improved local readiness for ship accidents and sufficient preincident planning